TWI753564B - Progressive addition lenses without narrow progressive corridor - Google Patents

Abstract

Provided is a progressive addition lens without a progressive corridor and capable of eliminating the peripheral unwanted astigmatism on both sides of the central progressive zone of the lens. The rear surface of the lens blank is processed to form a three-dimensional free-form surface, making it the lens of the present invention, which can provide a clear distance view on the top thereof, a clear near view on the bottom thereof, and a clear intermediate view thereof at the middle progressive zone. The present disclosure has a wide field of view and a high definition that greatly reduces the interference of vision in the peripheral unwanted astigmatism area.

Description

Progressive multifocal lenses without progressive narrow bands

The present invention relates to a multifocal lens, in particular to a progressive multifocal lens with greatly reduced peripheral astigmatism and no progressive narrow band.

As shown in FIG. 1 , the distance zone 1 of the conventional progressive addition lens is located in a wide area of the upper half of the lens, and is used to observe distant objects. When the human eye is in a relaxed head-up state, there is a correction for distance. The ability to use visual acuity to provide a clear and wide field of vision. The near zone 3 is located in the lower half of the lens and is used to observe near objects. The range of visual clarity is small. The progressive narrow zone 5 is located in the middle of the far zone and the near zone. It is used to observe objects at a medium distance, with a narrow range of visual clarity, while the peripheral astigmatism area 7 (also called blind area) is located on both sides of the lens and cannot be provided for users to observe. At the same time, it can be clearly seen from the contour map shown in FIG. 2 that the line spacing of the contour lines of the peripheral astigmatism area 7 is relatively dense, so the visual blur and shaking caused by the peripheral astigmatism area 7 will be very obvious and make the user feel dizzy Dizziness is uncomfortable.

In addition, the long-distance design will make the long-distance field of view wider, and then the breadth of the middle and short distances must be sacrificed, resulting in a narrower field of view for the middle and near use. Zone 3 is too narrow and requires frequent turning of the head to align the area to be viewed. It is easy to make the head tilt for a long time, resulting in fatigue and soreness due to compression of the shoulders and neck, and the eyes are likely to be tired and sore when the eyes look at the target through the near-use area of a small area for a long time.

Therefore, how to provide a better progressive addition lens (ie, a lens without a progressive narrow band and capable of greatly reducing the peripheral astigmatism on both sides of the middle area of the lens) while overcoming the aforementioned shortcomings is one of the current important issues.

In view of the above disadvantages of the prior art, the present invention provides a progressive addition lens without narrow progressive corridor.

According to an embodiment of the present invention, the progressive multifocal lens without progressive tape of the present invention takes the side facing the wearer's face as the rear surface and the side facing the outside as the front surface, and the rear surface of the lens is processed A preset three-dimensional space free-form surface is formed by means of the method, and the free-form surface has a distance zone, which is tied to the upper part of the lens; a near zone, which is tied to the lower part of the lens; and a middle zone, which is tied to the middle of the lens and is located between the distance Between the use area and the near-use area, the intermediate area increases the field of view through the free-form surface, forms no progressive narrow strip, and reduces the range of the peripheral astigmatism areas on both sides, and the range of the peripheral astigmatism area is the same as that of the The range ratio of the middle zone is 5% to 20%.

Preferably, the front surface of the lens is spherical or aspherical.

Preferably, the spherical or aspherical surface is determined according to the following formula: x ² +y ² +(1+Q)z ² -2zR=0, where x is the position of the lens surface x Cartesian coordinate system, and y is the lens surface y is the position of the rectangular coordinate system, z is the height of the surface, R is the radius of curvature of the vertex of the lens, and Q is the asphericity of the surface (Q=0 is spherical, Q≠0 is aspherical).

Preferably, the rear surface of the lens is a function of the height of the primary structure and the height of the secondary structure function combination.

Preferably, the height function of the main structure is determined by all or a partial combination of the shape functions of the Zernike function that control the change of the vertical degree, and the shape functions include Z ₃ to Z ₂₇ .

Preferably, the Zernike function is determined according to the following formula:

Among them, k is the k-th polynomial (integer of k≧0), x is the horizontal coordinate, y is the vertical coordinate, m is the angular frequency, n is the nth-order aberration, and a, b, and c are all integers ≧0 .

Preferably, the secondary structure height function is determined by including other Zernike functions Z ₆ to Z ₂₇ in addition to the Zernike function used for the main structure height function.

Preferably, the free-form surface includes sphero-cylindrical power and progressive multifocal power, and the sphero-cylindrical surface is determined according to the following formula: F(θ)=S+Csin ² (θ-α), R(θ)=(n ₂ -n ₁ )/F(θ), where S is the degree of sphere, C is the degree of cylinder, α is the cylinder axis, F(θ) is the degree of position at angle θ, and R(θ) is the degree of position at angle θ The radius of curvature of , n ₁ is the refractive index of the air (n ₁ =1.0), and n ₂ is the refractive index of the lens.

Preferably, the processing method of the rear surface of the lens is cutting processing.

Preferably, the rear surface of the lens is processed by cutting and polishing.

1: Remote area

3: Near-use area

5: Progressive tape

7: Peripheral astigmatism area

10: Remote use area

20: Near-use area

30: Middle Zone

P: lens blank

P1: Free-form surface of the rear surface of the lens

P2: Spherical or aspherical surface of the front surface of the lens

T: cutting tool

FIG. 1 is a schematic diagram of a conventional progressive addition lens; FIG. 2 is a contour map of the astigmatism of the conventional progressive addition lens; FIG. The contour map of the equivalent spherical power (M) simulated by the progressive multifocal lens (Φ=67mm) without the progressive tape according to the first embodiment of the invention; FIG. The contour map of the simulated astigmatism (J) of the focal lens (Φ=67mm); FIG. 6 shows the measured equivalent spherical power (M) of the progressive multifocal lens (Φ=67mm) without the progressive narrow band according to the second embodiment of the present invention ) contour diagram (wherein, only progressive addition lens (Φ=40mm) is shown); Figure 7 shows the measured astigmatism (J ) contour map (only progressive addition lenses are shown (Φ=40mm)); FIG. 8 shows the contour map of the equivalent spherical power (M) simulated by the progressive multifocal lens (Φ=67mm) without the progressive narrow band according to the second embodiment of the present invention; FIG. 9 shows the third embodiment of the present invention without the progressive power. The contour map of the astigmatism (J) simulated by the progressive multifocal lens (Φ=67mm) with the narrow strip; and FIG. 10 is a schematic diagram showing the processing process of the progressive multifocal lens without the progressive narrow strip of the present invention.

The following describes the implementation of the present invention through specific examples, and those skilled in the art can easily understand the advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied by other different specific examples, and various modifications and changes can be made to the details in the description of the present invention based on different viewpoints and applications without departing from the spirit of the present invention.

It should be noted that the structures, proportions, sizes, etc. shown in the accompanying drawings of the present invention are only used to cooperate with the contents disclosed in the description, so as to be read and understood by those who are familiar with the art, and are not used to limit the conditions for the implementation of the present invention. , so it has no technical significance, and any modification of the structure, the change of the proportional relationship or the adjustment of the size, without affecting the effect that the present invention can produce and the purpose that can be achieved, should fall within the scope of the present invention. The technical content must be within the scope of coverage.

Generally speaking, in the case of ignoring the thickness of the lens (thin lens), the total power of the lens can be determined by adding the power of the front surface and the back surface of the lens. In the present invention, the side facing the wearer's face is defined as the back surface, Towards the outside is the front surface, and the surface power of the lens is calculated from the refractive index (n) and radius of curvature (R) of the lens. Therefore, given the material of the lens, the refractive index of the lens can be determined. Then, as long as the shape changes of the front and back surfaces of the lens are determined, the Surface degrees.

Please refer to FIG. 3 , a progressive addition lens without narrow progressive corridor proposed by the present invention, the front surface of the lens is spherical or aspherical, and the back surface is processed to form a preset A three-dimensional free-form surface, the free-form surface has a far-use area 10, a near-use area 20 and an intermediate area 30, wherein the far-use area 10 is arranged on the upper part of the lens and has objects that can see the distance clearly, and the near-use area 20 is set The lower part of the lens has the ability to see objects at close range, and the middle area 30 is located in the middle of the lens and is between the far area 10 and the near area 20, and has the ability to see objects in the middle distance. In addition, the processing method can be cutting processing or after cutting processing and polishing treatment.

It is worth noting that the intermediate area of the present invention does not have a progressive narrow band, and the peripheral astigmatism areas on both sides of the intermediate area are largely eliminated, so that the progressive multifocal lens of the present invention has a wide field of view and greatly eliminates peripheral astigmatism that interferes with vision. That is, the ratio of the range of the peripheral astigmatism area to the range of the intermediate area is about 5%~20%, and the best is about 5%~10%.

If the surface of the present invention is spherical or aspherical, it is determined according to the following formula: x ² +y ² +(1+Q)z ² -2zR=0, (1) where x is the position of the lens surface x rectangular coordinate system, y is the position of the lens surface y rectangular coordinate system, z is the height of the surface, R is the radius of curvature of the vertex of the lens, and Q is the surface asphericity (Q=0 is spherical, Q≠0 is aspherical).

The rear surface of the progressive multifocal lens without progressive narrow strip of the present invention is processed to form a three-dimensional space free-form surface, and the free-form surface includes sphero-cylindrical power and progressive multifocal power. The above-mentioned sphero-cylindrical degree is determined according to the following formula: F(θ)=S+Csin ² (θ-α), (2) R(θ)=(n ₂ -n ₁ )/F(θ), ( 3) Among them, S is the sphere degree, C is the cylinder degree, α is the x cylinder axis, F(θ) is the degree at the angle θ, R(θ) is the radius of curvature at the angle θ, and n ₁ is the air Refractive index (n ₁ =1.0), n ₂ is the refractive index of the lens.

Furthermore, the above-mentioned progressive multifocal power system is designed on the rear surface, and the overall surface height function of the rear surface can be formed by combining both the main structure height function and the secondary structure height function.

The height function of the main structure is mainly used to design the height and change rate of the distance and near addition degrees, and is composed of all or part of the combination of the shape functions that control the change of the vertical degree in the Zernike polynomial. The shape functions include Z ₃ ~ Z ₂₇ (see Zernike polynomial below and shown in Table 1).

where the height function ( Z _k ( x , y )) of the lens surface geometry can be described by a combination of Zernike polynomials representing the shape of the aberration surface:

Among them, k is the k-th polynomial (integer of k≧0), x is the horizontal coordinate, y is the vertical coordinate, m is the angular frequency, n is the nth-order aberration, and a, b, and c are all integers ≧0 .

Furthermore, the high-order Zernike function added to the secondary structure height function without affecting the equivalent spherical power (M) distribution presented by the primary structure height function is mainly used to design the distribution, reduction and removal of astigmatism. In addition to the Zernike function used for the above-mentioned main structure height function, other higher-order Zernike functions such as Z ₆ ~Z ₂₇ are also included (please refer to the following Zernike polynomials and Table 1).

Using the above-mentioned lens full-surface height function of the present invention, the combination of Zernike polynomials up to 6th order and their representative Zernike coefficients can be deduced, wherein the Zernike coefficients are variable. Then, the equivalent spherical power and astigmatism of the lens can be calculated by bringing the representative coefficients into the equations according to the following formulas:

Among them, c _n ^m is the Zernike coefficient of the nth-order aberration angular frequency m, r is the simulated pupil radius (set to 4.5mm here), M is the equivalent spherical power, J ₀ is the orthogonal astigmatism power, and J ₄₅ is the Oblique astigmatism, J is the astigmatism.

In order to facilitate the understanding of the design of the progressive multifocal lens without progressive tapes of the present invention, the present invention provides the following specific embodiments, which are described below.

[First Embodiment]

In the first embodiment of the present invention, the material is PC (n=1.586), the prescription is plano/+2.00 Add, the diameter is 67mm, and the shape of the front surface of the progressive addition lens is designed as Q=0 (ball face) and the base arc is +4.50 D. Therefore, the shape of the rear surface of the progressive addition lens without the progressive tape of the present invention by cutting is designed as follows.

In the first embodiment of the present invention, the main structure height function is determined according to the following formula: Z _k (x,y)=C ₄ Z ₄ (x,y)+C ₇ Z ₇ (x,y)+C ₁₂ Z ₁₂ (x,y)+C ₁₇ Z ₁₇ (x,y)+C ₂₅ Z ₂₅ (x,y)=C ₄ √3(2x ² +2y ² -1)+C ₇ 2√2(3x ² y+3y ³ -2y)+C ₁₂ √5(6x ⁴ +12x ² y ² +6y ⁴ -6x ² -6y ² +1)+C ₁₇ √12(10x ⁴ y+20x ² y ³ +10y ⁵ - 12x ² y-12y ³ +3y)+C ₂₅ √14(15x ⁶ +15x ⁴ y ² -15x ² y ⁴ -20x ⁴ +6x ² -15y ⁶ +20y ⁴ -6y ² ) (9)

In the first embodiment of the present invention, the substructure height function is determined according to the following formula: Z _k (x,y)=0 (10)

The three-dimensional space data obtained by the calculation of the above formula is input into the cutting tool machine through the conversion program, and the rear surface shape of the progressive multifocal lens without progressive narrow band is formed through cutting processing. FIG. 4 shows the contour simulation diagram of the equivalent spherical power (M) of the progressive multifocal lens (Φ=67mm) without the progressive tape according to the first embodiment of the present invention, and FIG. 5 shows the first embodiment of the present invention without the progressive tape The astigmatism (J) contour simulation diagram of the progressive multifocal lens (Φ=67mm). It can be clearly seen from FIGS. 4 and 5 that, due to the absence of progressive narrow bands and the extremely small peripheral astigmatism area (the area where J≦+0.50 D is defined as an acceptable intermediate area), the progressive multifocal lens of the present invention has no progressive narrow bands. It has a wide field of view and high definition.

[Second Embodiment]

In the second embodiment of the present invention, the material is PC (n=1.586), and the prescription is- 2.50/+2.00 Add, diameter is 67mm, the shape of the front surface of the progressive addition lens is designed to be Q=0 (spherical) and the base arc is +2.25 D. FIG. 6 is a graph showing the measured contours of the equivalent spherical power (M) of the progressive multifocal lens (Φ=67mm) without the progressive narrow band according to the second embodiment of the present invention (wherein, only the progressive multifocal lens (Φ=40mm) is shown. )), Fig. 7 shows the measured astigmatism (J) contour line of the second embodiment of the progressive multifocal lens (Φ=67mm) without the progressive narrow band of the present invention (wherein, only the progressive multifocal lens (Φ=67mm) is shown 40mm)). It can be clearly seen from FIG. 6 and FIG. 7 that the progressive multifocal lens of the present invention without the progressive narrow band of the present invention has no progressive narrow band and greatly reduces the peripheral astigmatism area (the area where J≦+0.50 D is defined as an acceptable intermediate area). It has a wide field of view and high definition that greatly reduces peripheral astigmatism that interferes with vision.

As mentioned above, the detection methods of lens power distribution can be divided into optical and non-optical methods. Among them, optical methods can be divided into Moire optical interference technology and pre-waveguide aberration detection technology. Non-optical methods are mainly based on three-dimensional quantities. The bed scans the height changes on the lenses, which are then converted into a power distribution map.

The actual measurement map of the second embodiment of the present invention is that after the previous waveguide aberration detector measures the power of the entire surface of the lens to obtain data, the contour map is then drawn with MATLAB software. The actual mass-produced lens of the second embodiment has been tested by the instrument. The detection mainly takes the center point of the lens as the center of the circle, and the lens area with a diameter of 40 mm is the actual measurement range. The lens area within this range is sufficient to cover the current progressive multifocal point. All the important optical areas of the lens are shown in Figures 6 and 7, which show the non-progressive narrow zone and the peripheral astigmatism area of the lens of the second embodiment (the area defined as J≦+0.50D is the acceptable middle area) area) is only a relatively small area of the lens. Therefore, the progressive multifocal lens without the progressive narrow band of the present invention has a wide field of view and high definition.

[Third Embodiment]

In the third embodiment of the present invention, the material is PC (n=1.586), the prescription is plano/+2.00 Add, the diameter is 67mm, the shape of the front surface of the progressive addition lens is designed as Q=0 (spherical surface) and the base arc is +4.50 D. Therefore, the shape of the rear surface of the progressive addition lens without the progressive tape of the present invention is designed as follows.

In the third embodiment of the present invention, the primary structure height function is also determined according to the above formula, and the secondary structure height function is determined according to the following formula: Z _k (x,y)=C ₁₅ Z ₁₅ (x,y) =C ₁₅ √12(5x ⁴ y-10x ² y ³ +y ⁵ ) (11)

The three-dimensional space data obtained by the calculation of the above formula is input into the cutting tool machine through the conversion program, and the rear surface shape of the progressive multifocal lens without progressive narrow band is formed through cutting processing. FIG. 8 shows the contour simulation diagram of the equivalent spherical power (M) of the progressive multifocal lens (Φ=67mm) without the progressive tape of the third embodiment of the present invention, and FIG. 9 shows the third embodiment of the present invention without the progressive tape The astigmatism (J) contour simulation diagram of the progressive multifocal lens (Φ=67mm). It can be clearly seen from FIG. 8 and FIG. 9 that the progressive addition lens without progressive narrow band of the present invention has Wide field of view and high definition.

It is worth mentioning that the Zernike coefficients of the above-mentioned specific embodiments of the present invention are shown in Table 1.

In addition, as shown in FIG. 10 , the rear surface of the progressive multifocal lens without progressive narrow strips of the present invention is mainly a free-form surface formed in three-dimensional space by processing. In this way, the upper part of the lens can see objects at a distance, the lower part of the lens can see close objects clearly, and the middle area of the lens can see clearly Clear mid-range objects. The front surface of the lens of the present invention is a spherical or aspherical surface P2, and the back surface of the lens of the present invention is a free-form surface P1 in a three-dimensional space formed by processing a lens blank P whose spherical or aspherical surface is the base arc. The processing method is cutting processing, or after cutting processing and polishing treatment, the lens of the present invention is formed. The cutting tool T in FIG. 10 is only a schematic representation of the processing method, and is not limited thereto. Therefore, the progressive multifocal lens without progressive narrow bands of the present invention can have the advantages of wide field of view and high definition with minimal peripheral astigmatism that interferes with vision.

As mentioned above, the present invention can directly use commercially available lens blanks to process and manufacture the rear surface of the lens by cutting according to the different needs of users, to form the free-form surface, and also according to various needs. Processing it, such as coating, strengthening, anti-reflection, anti-fog, discoloration, etc., can not only reduce the cost of mold development, but also reduce the cost of inventory.

The lens blank referred to in the present invention generally refers to a mold with a preset curvature that is formed with an optical power at least on the front surface of the lens, or with a basic power on the front and rear surfaces of the lens. The rear surface of the lens blank is then processed and polished to achieve the prescription required by consumers.

The above-mentioned embodiments are only used to illustrate the effect of the present invention, but not to limit the present invention. Anyone skilled in the art can modify or change the above-mentioned embodiments without departing from the spirit and scope of the present invention. In addition, the functions in the above embodiments are only illustrative, and are not intended to limit the present invention. Therefore, the protection scope of the present invention should be as listed in the following patent application scope.

10: Remote use area

20: Near-use area

30: Middle Zone

Claims (8)

A progressive multifocal lens without a progressive narrow band, the side facing the wearer's face is defined as the back surface, the side facing the outside is the front surface, and a preset free-form surface is formed on the rear surface of the lens by processing, the The free-form surface has a distance zone, which is tied to the upper part of the lens; a near zone, which is tied to the lower part of the lens; and a middle zone, which is tied to the middle of the lens and is between the distance zone and the near zone, and A peripheral astigmatism area is formed on both sides, wherein, the middle area is formed by the free curved surface to increase the field of view, and does not have a progressive narrow band, and reduces the area of the peripheral astigmatism area on both sides, and the range of the peripheral astigmatism area is the same as that of the intermediate area. The range ratio is 5% to 20%, wherein the front surface of the lens is spherical or aspherical, and wherein the spherical or aspherical surface is determined according to the following formula: x ² +y ² +(1+Q)z ² - 2zR=0, where x is the position of the lens surface x rectangular coordinate system, y is the position of the lens surface y rectangular coordinate system, z is the surface height, R is the radius of curvature of the lens vertex, Q is the surface asphericity (Q=0 is Spherical, Q≠0 is aspheric). The progressive multifocal lens without a progressive tape as described in claim 1, wherein the rear surface of the lens is composed of a main structure height function and a sub structure height function. The progressive multifocal lens without progressive narrow band as described in item 2 of the claimed scope, wherein the main structure height function is determined by all or part of the combination of the shape functions controlling the change of the vertical power in the Zernike function, and the shape functions include Z ₃ ~Z ₂₇ . The progressive multifocal lens without progressive narrow band described in item 3 of the scope of the patent application, wherein the Zernike function is determined according to the following formula:

Among them, k is the k-th polynomial (integer of k≧0), x is the horizontal coordinate, y is the vertical coordinate, m is the angular frequency, n is the nth-order aberration, and a, b, and c are all integers ≧0 . The progressive multifocal lens without the progressive narrow band described in the second claim of the scope of application, wherein the secondary structure height function includes other Zernike functions Z ₆ to Z ₂₇ in addition to the Zernike function used for the main structure height function. Sure. The progressive multifocal lens without progressive narrow band as described in the first claim of the scope of application, wherein the free-form surface includes a sphero-cylindrical power and a progressive multi-focal power, and the sphero-cylindrical surface is determined according to the following formula: F(θ)= S+Csin ² (θ-α), R(θ)=(n ₂ -n ₁ )/F(θ), where S is the sphere degree, C is the cylinder degree, α is the cylinder axis, F(θ) is the degree at the angle θ, R(θ) is the radius of curvature at the angle θ, n ₁ is the refractive index of air (n ₁ =1.0), and n ₂ is the refractive index of the lens. The progressive multifocal lens without progressive narrow band according to claim 1, wherein the processing method of the rear surface of the lens is cutting processing. The progressive multifocal lens without progressive narrow band as described in claim 1, wherein the back surface of the lens is processed by cutting and polishing.

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